Mobile terminal and method of generating key signal therein

ABSTRACT

A mobile terminal and method of generating a key signal therein are disclosed, by which the key signal can be generated in a manner of adjusting touch sensitivity. The present invention includes a touchpad for a key signal input, a controller generating a key signal corresponding to a touched position if the touchpad is touched by a user and a strength of the touch is equal to or greater than a reference value, and a sensitivity adjusting unit adjusting the reference value.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No.10-2007-0055490, filed on 7 Jun. 2007, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile terminal, and moreparticularly, to a mobile terminal and method of generating a key signaltherein. Although the present invention is suitable for a wide scope ofapplications, it is particularly suitable for generating a key signal ina mobile terminal having a touchpad.

2. Discussion of the Related Art

Generally, a mobile terminal is provided with an input device for a keysignal input. And, a user is able to input a key signal.

Recently, in order to facilitate a user to input a key signal, a mobileterminal tends to be equipped with various input devices. And, one ofthe various input devices is a touch type input device.

However, sensitivity to a touch is fixed in a mobile terminal having atouch type input device according to a related art. So, a user is unableto adjust sensitivity separately and thus it may be inconvenient toinput a key signal using a conventional touch type input device.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a mobile terminal andmethod of generating a key signal therein that substantially obviate oneor more problems due to limitations and disadvantages of the relatedart.

An object of the present invention is to provide a mobile terminal andmethod of generating a key signal therein, by which the key signal canbe generated in a manner of adjusting touch sensitivity.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amobile terminal according to the present invention includes a touchpadfor a key signal input, a controller generating a key signalcorresponding to a touched position if the touchpad is touched by a userand a strength of the touch is equal to or greater than a referencevalue, and a sensitivity adjusting unit adjusting the reference value.

In another aspect of the present invention, a method of generating a keysignal in a mobile terminal, having a touchpad includes detecting atouch of the touchpad by a user, and generating the key signalcorresponding to a touched position of the touchpad if a strength of thetouch is equal to or greater than a reference value, wherein thereference value is adjustable.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a block diagram of a mobile terminal according to oneembodiment of the present invention;

FIG. 2 is a flowchart for a method of generating a key signal in amobile terminal according to one embodiment of the present invention;

FIG. 3 is a flowchart for a method of adjusting a reference value in themobile terminal shown in FIG. 1;

FIG. 4 is a diagram of a mobile terminal to explain an example that thereference value adjusted by the method shown in FIG. 3 is differentlyapplied per an area; and

FIGS. 5 to 8 are diagrams to explain a method of generating a key signalin a mobile terminal according to one embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. It is to be understood by those of ordinary skill in thistechnological field that other embodiments may be utilized, andstructural, electrical, as well as procedural changes may be madewithout departing from the scope of the present invention. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

A mobile terminal according to one embodiment of the present inventionand a method of generating a key signal therein are explained withreference to the accompanying drawings as follows.

A mobile terminal described in this disclosure may include an electronicdevice portable by a user. For instance, the mobile terminal includesone of a mobile phone, a digital broadcasting terminal, an MP3 player, aPDA (personal digital assistants), a PMP (portable multimedia player)and the like.

FIG. 1 is a block diagram of a mobile terminal according to oneembodiment of the present invention.

Referring to FIG. 1, a mobile terminal 100 according to one embodimentof the present invention includes a controller 110, a touchpad 120, asensitivity adjusting unit 130, a display 140, a wireless communicationunit 150 and a memory 160. The mobile terminal 100 shown in the drawingjust means a single embodiment only, by which the present invention isnot restricted. In particular, elements of the embodiment shown in thedrawing can be omitted in part to configure a mobile terminal of thepresent invention or elements not shown in the drawing can be added to amobile terminal of the present invention in accordance with anembodiment type.

FIG. 2 is a flowchart for a method of generating a key signal in amobile terminal according to one embodiment of the present invention.

Referring to FIG. 1 and FIG. 2, in case that the touchpad 120 of themobile terminal 100 is touched, the controller 1 10 is able to detectthe touch [S10]. The touch to the touchpad 120 can be carried out usinga user's finger. In this case, the touchpad 120 is an input device for akey signal input to the mobile terminal.

Meanwhile, the controller 110 is able to generate a specific key signalcorresponding to a touched position only if a strength of the touch isequal to or greater than a reference value [S20, S30]. So, if thestrength of the touch is smaller than the reference value, thecontroller 110 may not generate a key signal [S20, S40].

The reference value can be regarded as an example of a threshold valuefor a keys signal generation. And, the reference value can be stored asa default in the memory 160.

The reference value can be adjusted via the sensitivity adjusting unit130. If the reference value is adjusted, the controller 110 is able togenerate a specific key signal corresponding to a touched position onlyif a strength of the touch is equal to or greater than the adjustedreference value. And, the reference value in the adjusted state can bestored in the memory 160.

The wireless communication unit 150 performs radio-frequency processingon a signal for wireless communication. For instance, the wirelesscommunication unit 150 modulates a signal into a radio-frequency signalfor transmission and demodulates a received radio-frequency signal.

FIG. 3 is a flowchart for a method of adjusting the reference valueaccording to one embodiment of the present invention.

Referring to FIG. 3, a touch sensitivity mode can be entered via a keysignal input [S110]. In this case, the key signal input can be carriedout via the touchpad 120 or an input device (not shown in the drawing)provided to the mobile terminal 100 regardless of the touchpad 120.

The touch sensitivity mode entry can be carried out via a menu key inputor a specific shortcut key input.

If the touch sensitivity mode is entered via the menu or shortcut keyinput, the sensitivity adjusting unit 130 is able to adjust a referencevalue. For instance, the sensitivity adjusting unit 130 can raise orlower a set reference value. And, the sensitivity adjusting unit 130 canselect a defaulted reference value [S120]. It is understood that thedefaulted reference value can be modified via a user's key manipulation.Thus, if the reference value is adjusted, a user is able to confirm theadjusted reference value on an idle image [S130].

If a user is satisfied with the reference value adjusted via the stepsS10 to S130, the reference value adjusting process is completed.Otherwise, the user can repeat the steps S110 to S130.

The above-explained reference value can be an index that indicates touchsensitivity of the touchpad 120. For instance, the lower the referencevalue becomes, the more sensitive to the touch the touchpad 120 becomes.The higher the reference value becomes, the less sensitive to the touchthe touchpad 120 becomes.

According to one embodiment of the present invention, the referencevalue is collectively applicable to the touchpad 120 or differentlyapplicable to the touchpad 120 per an area. FIG. 4 is a diagram of amobile terminal to explain an example that the reference value isdifferently applied per an area.

Referring to FIG. 4, a reference value for a central part (indicated bya dotted line) of a numeral key ‘5’ is set to 100 and a reference valueof a peripheral part thereof is set to 200. Thus, if the referencevalues are set, the central part is more sensitive to a touch and theperipheral part is less sensitive to a touch. So, even if two keys aresimultaneously pressed, the controller 110 can decide an input of asingle key signal.

Hence, the controller 110 is able to generate a key signal correspondingto a position from which a touch having a strength equal to or greaterthan the reference value is detected. For instance, assuming that auser's finger simultaneously presses both a numeral key ‘5’ and anumeral key ‘6’, if most of the user's finger touches the numeral key‘5’ while the reset of the user's finger touches the numeral key ‘6’,the controller 110 is able to generate a key signal corresponding to thenumeral key ‘5’ only by considering the reference value (reference valueof central part is low, reference value of peripheral part is high).

Meanwhile, the touchpad 120 of the mobile terminal 100 according to oneembodiment of the present invention can form a mutual layer structurewith the display 140.

In one embodiment, a key icon can be displayed on the display 140 togenerate a key signal input from the touchpad 120.

In this disclosure, an example of ‘key icon’ is a keypad displayed onthe display 140. Through the keypad, numeral keys, character keys,navigation keys and the like can be inputted. So, the key icon (cf.‘141’ in FIG. 5) is able to generate the key signal input from thetouchpad 120.

According to one embodiment of the present invention, the controller 110is able to vary a size of the key icon 141 in accordance with areference value modification by the sensitivity adjusting unit 130.

As mentioned in the foregoing description, the variation example of thekey icon 141 is shown in FIG. 5.

If the reference value is modified higher (i.e., sensitivity of touch islowered), the key icon 141, as shown in (a) of FIG. 5, is displayedlarger. If the reference value is modified lower (i.e., sensitivity oftouch is raised), the key icon 141, as shown in (b) of FIG. 5, isdisplayed smaller.

For instance, in case that a user has poor vision or weak motor skills,the user causes the mobile terminal 100 to display the key icon 141, asshown in (a) of FIG. 5, relatively larger to enhance convenience for thekey signal input. In case that a user has good vision or strong motorskills, the user causes the mobile terminal 100 to display the key icon141, as shown in (b) of FIG. 5, smaller to receive more commands.

According to one embodiment of the present invention, the referencevalue can vary in accordance with a mode selection of a displayed image.In particular, a first image mode has a touch sensitivity relativelyless sensitive and a second image mode has a touch sensitivityrelatively more sensitive.

For instance, if a user with poor vision or with weak motor skills, theuser causes the mobile terminal 100 to select the first image mode anddisplays the key icon 141, as shown in (a) of FIG. 5, in a large size toenhance convenience for key signal input. In this case, the referencevalue is relatively higher than the reference value of the second imagemode.

If a user is a user with good vision or strong motor skills, the usercauses the mobile terminal 100 to select the second image mode anddisplays the key icon 141, as shown in (b) of FIG. 5, in a small size toreceive more commands. In this case, the reference value is relativelyhigher than the reference value of the first image mode.

In the above-explained embodiment, the varying reference value and thevarying size of the key icon 141 can be stored and memorized in thememory 160.

Conversely, in another embodiment, the sensitivity of the touch screenmay vary upon selection of a display size. That is, if a user selectsthe larger key display of FIG. 5A, the sensitivity of the keysautomatically drops. And when a user selects the smaller key display ofFIG. 5B, the sensitivity of the keys automatically increases.

According to one embodiment of the present invention, the controller 110is able to display a phonebook image in a prescribed area of the keyicon 141. This example is shown in FIG. 6. For instance, an areaprovided for a numeral key input can become the prescribed area of thekey icon 141.

For instance, if a user has poor vision or weak motor skills, the usercauses the mobile terminal 100 to select the first image mode anddisplays the phonebook image, as shown in (a) of FIG. 6, in a large sizeto enhance convenience for key signal input. In this case, the referencevalue is relatively higher than the reference value of the second imagemode.

If a user has good vision or strong motor skills, the user causes themobile terminal 100 to select the second image mode and displays thephonebook image, as shown in (b) of FIG. 6, in a small size to display amore number of phonebook images. In this case, the reference value isrelatively higher than the reference value of the first image mode.

Namely, according to one embodiment of the present invention, thecontroller 110 is able to vary the number of the displayed phonebookimages in accordance with the reference value. The varied phonebookimage number can be stored and memorized in the memory 160.

In the case shown in (a) or (b) of FIG. 6, it is able to display adifferent phonebook image using a scroll key (not shown in the drawing)or a navigation key (not shown in the drawing).

In this case, if a key signal is inputted by having a displayedphonebook image touched, the controller 110 is able to make a call to aphone number that matches the phonebook image. Namely, a user of themobile terminal 100 is able to make a call in a simple manner byconfirming the displayed phonebook image only.

Besides, the displayed phonebook image can be interconnected to anabbreviated number.

For instance, an image interconnected to an abbreviated number ‘1’ canbe displayed in an area of the key icon 141 provided for an input of anumeral key ‘1’. And, an image interconnected to an abbreviated number‘2’ can be displayed in an area of the key icon 141 provided for aninput of a numeral key ‘2’.

According to one embodiment of the present invention, in case that areference value is modified by the sensitivity adjusting unit 130, thecontroller 110 is able to generate a key signal by subdividing an areaof the touchpad 120 corresponding to a specific key signal input of thekey icon.

In this case, the specific key signal can include a navigation keysignal.

FIG. 7 is a diagram to explain a key signal generating method in casethat a specific key relevant to area subdivision of the touchpad 120 s anavigation key.

In (a) of FIG. 7, depicted is a case that a reference value is set highwhen a navigation key 141a is allocated to a touchscreen. In the caseshown in (a) of FIG. 7, for instance, when a key signal identicallyworks on any part of an area allocated to a left direction key, if anarea of the touchpad 120 relevant to the left direction key is touchedonce, the controller 110 shifts a position of a cursor or a position ofa highlight in a left direction by a single space. Namely, in (a) ofFIG. 7, depicted is a case that an area of the touchpad 120 is notsubdivided.

In (b) of FIG. 7, depicted is a case that a reference value is set lowwhen a navigation key 141a is allocated to a touchscreen. In this case,the controller 110 divides a left direction key into three equal parts.And, the controller 110 generates a key signal of a cursor or highlightposition shift command for shifting three spaces to correspond to anouter part, a key signal of a cursor or highlight position shift commandfor shifting two spaces to correspond to a middle part, and a key signalof a cursor or highlight position shift command for shifting one spaceto correspond to an inner part.

It is understood that the above description is identically applied to aright direction key, a down-direction key and an up-direction key.

According to one embodiment of the present invention, the controller 110is able to differentiate an extent of subdivision in accordance with areference value variation (sensitivity variation to a touch). Forinstance, if a reference value gets lower than that of the case shown in(b) of FIG. 7, an area can be subdivided into five equal parts. Thesubdivision extent can be stored and memorized in the memory 160.

According to one embodiment of the present invention, if a specific areaof the touchpad 120 relevant to a specific key signal from the key icon141 is touched, the controller 110 enlarges and displays the touchedspecific area. This example is shown in FIG. 8.

In (a) of FIG. 8, depicted is a case that the key icon 141 is nottouched. In (b) of FIG. 8, depicted is a case that an area correspondingto a numeral key ‘1’ is enlarged and displayed if the numeral key ‘1’ ofthe key icon 141 is touched. In (c) of FIG. 8, depicted is a case thatan area corresponding to a numeral key ‘2’ is enlarged and displayed ifthe numeral key ‘2’ of the key icon 141 is touched. Thus, if the touchedarea is enlarged and displayed, a user is able to make sure what kind ofkey the user has touched.

Accordingly, the present invention generated a key signal by adjustingtouch sensitivity in a mobile terminal having a touchpad, therebyenhancing user's convenience in inputting key signals.

Various embodiments described herein may be implemented in acomputer-readable medium using, for example, computer software,hardware, or some combination thereof. For a hardware implementation,the embodiments described herein may be implemented within one or moreapplication specific integrated circuits (ASiCs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,other electronic units designed to perform the functions describedherein, or a selective combination thereof.

For a software implementation, the embodiments described herein may beimplemented with separate software modules, such as procedures andfunctions, each of which perform one or more of the functions andoperations described herein. The software codes can be implemented witha software application written in any suitable programming language andmay be stored in memory, and executed by a controller or processor.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A mobile terminal, comprising: a display including a touchpad; acontroller operatively connected to the touchpad and configured togenerate a key signal when a predetermined position of the touchpad istouched and a strength of the touch is equal to or greater than athreshold value; and a sensitivity adjusting unit configured to adjustthe threshold value.
 2. The mobile terminal of claim 1, wherein thesensitivity adjusting unit is configured to adjust the threshold valuein response to a user input.
 3. The mobile terminal of claim 1, whereinthe touchpad is divided into a plurality of areas, each of the pluralityof areas configured to generate a corresponding one of a plurality ofsignals, and the sensitivity adjusting unit is configured to adjust afirst threshold value for a first of the plurality of areas, and toadjust a second threshold value for a second of the plurality of areas,the second threshold value being different from the first thresholdvalue.
 4. The mobile terminal of claim 1, wherein the touchpad isdivided into a plurality of areas, each of the plurality of areasconfigured to generate a corresponding one of a plurality of signals, atleast one of the plurality of areas having an inner area and an outerarea, the inner area having an inner area threshold value lower than anouter area threshold value of the outer area.
 5. The mobile terminal ofclaim 4, wherein the sensitivity adjusting unit is configured to adjustat least one of the inner area threshold value and the outer areathreshold value.
 6. The mobile terminal of claim 1, wherein the displayis configured to display a key pad on the touchpad, the key padincluding a plurality of keys, each of the plurality of keys arranged togenerate a corresponding one of a plurality of key signals.
 7. Themobile terminal of claim 6, wherein the controller is configured to varya size of one of the plurality of keys when the threshold value of theone key is modified by the sensitivity adjusting unit.
 8. The mobileterminal of claim 7, wherein the controller is configured to enlarge asize of the one key when the threshold value of the one key is reduced,and reduce the size of the one key when the threshold value of the onekey is increased.
 9. The mobile terminal of claim 6, wherein thesensitivity adjusting unit is configured to modify the threshold valueof one of the plurality of keys when a size of the one key is varied bythe controller.
 10. The mobile terminal of claim 9, wherein thecontroller is configured to reduce the threshold of the one key when thesize of the one key is enlarged, and increase the threshold of the onekey when the size of the one key is reduced.
 11. The mobile terminal ofclaim 6, further comprising: a memory configured to store a phonebookincluding a plurality of images, wherein the controller is configured todisplay at least one image stored in the phonebook on a prescribed areaof the key pad.
 12. The mobile terminal of claim 11, wherein thecontroller is configured to enlarge the at least one image when thethreshold value is decreased; reduce the at least one image when thethreshold value is increased.
 13. The mobile terminal of claim 12,wherein the controller is configured to initiate a call to a phonenumber matching a displayed phonebook image upon recognizing a touch ofthe displayed phonebook image.
 14. The mobile terminal of claim 11,wherein the controller is configured to decrease the threshold valuewhen the at least one image is enlarged; and increase the thresholdvalue when the at least one image is reduced.
 15. The mobile terminal ofclaim 14, wherein the controller is configured to initiate a call to aphone number matching a displayed phonebook image upon recognizing atouch of the displayed phonebook image.
 16. The mobile terminal of claim11, wherein the controller is configured to vary a number of the atleast one image displayed on the key pad in accordance with anadjustment of the threshold value.
 17. The mobile terminal of claim 16,wherein the controller is configured to increase the number of displayedimages when the threshold value is decreased and to decrease the numberof displayed images when the threshold value is increased.
 18. Themobile terminal of claim 17, wherein the controller is configured toinitiate a call to a phone number matching a displayed phonebook imageupon recognizing a touch of the displayed phonebook image.
 19. Themobile terminal of claim 11, wherein the controller is configured tovary the threshold value in accordance with an adjustment of a number ofthe at least one image displayed on the key pad.
 20. The mobile terminalof claim 19, wherein the controller is configured to increase thethreshold value when the number of displayed images is decreased and todecrease the threshold value when the number of displayed images isincreased.
 21. The mobile terminal of claim 20, wherein the controlleris configured to initiate a call to a phone number matching a displayedphonebook image upon recognizing a touch of the displayed phonebookimage.
 22. The mobile terminal of claim 6, wherein the controller isconfigured to generate the key signal by subdividing an area of thetouchpad corresponding to a specific signal when the reference value isadjusted by the sensitivity adjusting unit.
 23. The mobile terminal ofclaim 22, wherein the specific key signal comprises a navigation keysignal.
 24. The mobile terminal of claim 23, wherein the controller isconfigured to generate an increment for a direction shift in accordancewith the subdivided area differently.
 25. The mobile terminal of claim24, wherein the controller is configured to generate a subdivisionextent when the threshold value is modified by the sensitivity adjustingunit.
 26. The mobile terminal of claim 6, wherein the controller isconfigured to enlarge one of the plurality of keys when a specific areaof the one key is touched.
 27. A method of generating key signals in amobile terminal having a touchpad, the method comprising: generating akey signal when a predetermined position of the touchpad is touched anda strength of the touch is equal to or greater than a threshold value;and adjusting the threshold value.
 28. The method of claim 27, whereinthe step of adjusting the threshold value comprises: adjusting thethreshold value in response to a user input.
 29. The method of claim 27,further comprising: dividing the touchpad into a plurality of areas,each of the plurality of areas configured to generate a correspondingone of a plurality of signals; adjusting a first threshold value for afirst of the plurality of areas; and adjusting a second threshold valuefor a second of the plurality of areas, the second threshold value beingdifferent from the first threshold value.
 30. The method of claim 27,further comprising: dividing the touchpad into a plurality ofareas,.each of the plurality of areas configured to generate acorresponding one of a plurality of signals, at least one of theplurality of areas having an inner area and an outer area, the innerarea having an inner area threshold value lower than an outer areathreshold value of the outer area; and adjusting at least one of theinner area threshold value and the outer area threshold value.
 31. Themethod of claim 27, further comprising: displaying a key pad on thetouchpad, the key pad including a plurality of keys, each of theplurality of keys arranged to generate a corresponding one of aplurality of key signals; and varying a size of one of the plurality ofkeys when a threshold value of the one key is adjusted.
 32. The methodof claim 31, wherein the step of varying a size of one of the pluralityof keys comprising: enlarging a size of the one key when the thresholdvalue of the one key is reduced; and reducing the size of the one keywhen the threshold value of the one key is increased.
 33. The method ofclaim 27, further comprising: displaying a key pad on the touchpad, thekey pad including a plurality of keys, each of the plurality of keysarranged to generate a corresponding one of a plurality of key signals;and adjusting a threshold value of one of the plurality of keys when asize of the one key is varied.
 34. The method of claim 33, the step ofadjusting the threshold value of one of the plurality of keyscomprising: reducing the threshold of the one key when the size of theone key is enlarged; and increasing the threshold of the one key whenthe size of the one key is reduced.
 35. The method of claim 27, furthercomprising: displaying a key pad on the touchpad, the key pad includinga plurality of keys, each of the plurality of keys arranged to generatea corresponding one of a plurality of key signals; storing a phonebookincluding a plurality of images in a memory; and displaying at least oneimage stored in the phonebook on a prescribed area of the key pad. 36.The method of claim 35, further comprising: enlarging the at least oneimage when the threshold value is decreased, reducing the at least oneimage when the threshold value is increased.
 37. The method of claim 36,further comprising: initiating a call to a phone number matching adisplayed phonebook image upon recognizing a touch of the displayedphonebook image.
 38. The method of claim 35, further comprising:decreasing the threshold value when the at least one image is enlarged;and increasing the threshold value when the at least one image isreduced.
 39. The method of claim 38, further comprising: initiating acall to a phone number matching a displayed phonebook image uponrecognizing a touch of the displayed phonebook image.
 40. The method ofclaim 35, further comprising: varying a number of the at least one imagedisplayed on the key pad in accordance with an adjustment of thethreshold value.
 41. The method of claim 40, the step of varying anumber of the at least one image comprising: increasing the number ofthe at least one image when the threshold value is decreased; anddecreasing the number of the at least one image when the threshold valueis increased.
 42. The method of claim 41, further comprising: initiatinga call to a phone number matching a displayed phonebook image uponrecognizing a touch of the displayed phonebook image.
 43. The method ofclaim 40, further comprising: varying the threshold value in accordancewith an adjustment of a number of the at least one image displayed onthe key pad.
 44. The method of claim 43, the step of varying thethreshold value comprising: increasing the threshold value when thenumber of the at least one image is decreased; and decreasing thethreshold value when the number of the at least one image is increased.45. The method of claim 44, further comprising: initiating a call to aphone number matching a displayed phonebook image upon recognizing atouch of the displayed phonebook image.
 46. The method of claim 27,further comprising: generating one of a plurality of key signals bysubdividing an area of the touchpad corresponding to a specific signalwhen the reference value is adjusted.
 47. The method of claim 46,wherein the specific key signal comprises a navigation key signal. 48.The method of claim 47, further comprising: generating an increment fora direction shift in accordance with the subdivided area differently.49. The method of claim 48, further comprising: generating a subdivisionextent when the threshold value is adjusted.
 50. The method of claim 27,further comprising: displaying a key pad on the touchpad, the key padincluding a plurality of keys, each of the plurality of keys arranged togenerate a corresponding one of a plurality of key signals; andenlarging one of the plurality of keys when a specific area of the onekey is touched.